Hydraulic jacks are common devices used in daily life for jacking a load to a predetermined height with a considerably small force. The working principle of the hydraulic jack is as follows. An applied small force moves an input piston of small cross-sectional area and pushes fluid oil into an output oil cylinder, which then forces an output piston of large cross-sectional area to jack up the load.
According to the law of energy conversion, the path of the input piston is far longer than that of the output piston. Therefore the input piston must be repeatedly pumped to jack a load to a certain height. During the jacking process, each stroke of the input piston moves the output piston the same distance, regardless of the load. Therefore the same number of pumping strokes is needed to jack the load to a certain height, regardless of whether it is a zero load, a small load or a heavy load. The jacking process is slow, as well as time and effort consuming.
For that reason, there is a need for a system to overcome the drawbacks of currently available jacks, such as described above.